1. Field of the Invention
The present invention relates to a seal structure.
The present invention, more particularly, relates to a seal structure providing a waterproof structure of an electronic device and a connector.
2. Description of the Conventional Art
In recent days, a waterproof connector used in an electronic device such as a cellular phone or the like, a wire harness for a motor vehicle and the like makes progress in downsizing, and a high waterproof function is demanded.
In order to provide the waterproof function to the electronic device comprising a plurality of spaces, it is necessary to provide airtightness to a housing constructing each of the spaces, and electrically connect between the spaces by a flexible board or the like.
In this case, there have been proposed a method of setting a terminal at a wall surface of the housing comparting each of the spaces, and connecting between the terminals by a wiring member, and a method of setting the wiring member through the wall surface of the housing and filling a gap made between the wiring member and the housing with an adhesive agent or the like.
However, the constitution that the terminal is provided at the wall surface of the housing has a problem that the device is enlarged in size. The method of filling the gap made between the wiring member and the housing with the adhesive agent or the like causes a problem that disassembly and reassembly are difficult.
Accordingly, as shown in FIGS. 4 and 5, there has been proposed a constitution of integrally molding seal members with a flexible wiring board (Japanese Unexamined Patent Publication No. 2003-142836 and Japanese Unexamined Patent Publication No. 2004-214927).
In a constitution shown in FIG. 4, frame body shaped seal members 301 corresponding to shapes of respective housings (not shown) are integrally formed with a flexible wiring board 100.
The flexible wiring board 100 extends through each of the seal members 301, and electronic parts are mounted within regions surrounded by the respective seal members 301.
Further, in a constitution shown in FIG. 5, bush shaped seal members 303 are integrally formed with a flexible wiring board 100.
The seal members 303 are installed to insertion holes provided in respective housings (not shown).
Further, connectors 304 provided at both ends of the flexible wiring board 100 are electrically connected to electric parts within the housings.
However, each of the flexible wiring boards 100 with shielding layers shown in FIGS. 4 and 5 is provided with the following structure.
Electromagnetic shielding layers using a silver paste are provided on both surfaces of a base FPC which is structured such that a circuit pattern made of a cupper foil is sandwiched by an elastic material such as a polyimide, a polyamide, a polyester, a liquid crystal polymer, a polyethylene naphthalate or the like, and insulating layers are formed on surfaces of the electromagnetic shielding layers for protecting and electrically insulating the surfaces.
This insulating layer is called as a top coat, and an alkyd resin is used.
However, the insulating layer has a bad affinity with respect to the seal members 301 and 303, and it is hard to integrally fix the seal members 301 and 303 on the insulating layer.
Therefore, there has been employed a method of peeling off the insulating layer at a position where the seal member 301 or 303 is arranged, and then integrally forming the seal members 301 or 303 thereon.
Accordingly, it takes a lot of work to peel off the insulating layer, and a manufacturing cost is high.
Further, since the insulating layer is peeled off even partly, a service life of the electromagnetic shielding layer is adversely affected.